We have obtained rotavirus cDNA clones from several genes of various rotavirus strains. They include the human strains Wa, DS1, Price, M-37 and ST3 and animal strains NCDV, RRV, UK and OSU. Either single-stranded (ss) or double-stranded (ds) rotavirus RNA was employed as template for reverse transcription and cDNA synthesis; after second strand synthesis the cDNAs were introduced into pBR322 by the dC:dG tailing method. Transformation with the rotavirus/pBR322 recombinant plasmids yielded a large number of clones carrying rotavirus gene copies. The rotavirus gene segement cDNA present in the clones was identified by Northern blot hybridization or colony hybridization with cDNAs of known gene origin. Clones carrying copies of the genes encoding the outer capsid hemagglutinin (gene 4) from the simian RRV and the bovine UK rotavirus have been identified and the RRV gene 4 has been partially sequenced. Clones with copies of the VP7 glycoprotein gene of the animal rotaviruses OSU, NCDV, RRV and several human rotavirus strains have been identified, characterized by restriction mapping and some have been sequenced partially or in their entirety.